However, the giant Belgian returns to Goodison Park on Sunday a shadow of the player who terrorised defences for so long and is showing little evidence of turning around his sharp decline.

Fellaini is in alien territory and has visibly suffered all season under the lights at Old Trafford, feeling the pressure of enormous expectation week after week. After all, he had been on a steady incline career-wise ever since his move to the Premier League in 2008.

FELLAINI'S DIFFICULT DEBUT SEASON

GAMES

DUEL SUCCESS

AERIAL DUEL SUCCESS

TACKLE SUCCESS

FELLAINI

15

50.46%

53.33%

70%

CARRICK

24

62.76%

64.52%

66.04%

CLEVERLEY

21

51.83%

27.27%

82.61%

Having realised a dream of playing for one of the biggest clubs in world football, let alone an English football institution, the Belgian has discovered that the game gets tougher the higher you climb. It has been a rude awakening.

But can all the blame be placed on the 26-year-old? After all, he moved to United knowing he would be linking up with the manager who helped him forge a reputation as one of the most effective second strikers in football. Life at Everton may not have yielded trophies but he was a vital cog in a system that very much fed to his strengths.

Moyes has been attacked from all sides this season, leading the champions to what looks likely to be their lowest domestic finish in 24 years (previously 13th in 1989-90). But Fellaini, a Moyes disciple - a vital conduit in the dressing room and someone the Scot could rely on to promote the style of play he would want to impose - has not come close to justifying his £27.5 million price tag.

And that in itself is a problem. Moyes, a naturally pragmatic manager has so far failed to show enough conviction to stay true to the style that brought him success at Everton. Yes, they were not a solely limited long ball team, but that was certainly a strong theme at Goodison Park and a mantra that proved effective in his time on Merseyside.

To get the best out of Fellaini you have to play to what seems his obvious strength; his ability in the air. Yet, oddly, this has not been possible in 2013-14.

Moyes has explained in the past that he would feel uncomfortable substituting Robin van Persie if United were chasing a game, lending weight to the theory that he lacks the assurance to completely overhaul the system at Old Trafford.

There have been games - Bayern Munich away for example - where United have resorted to that style but it was circumstance as the underdog rather than a legitimate plan which led to the change in approach.

So with Moyes intent on staying true to the Sir Alex Ferguson years, Fellaini has been asked to play a much deeper role than he is accustomed to. His attributes hardly scream ball-playing central midfielder and the evidence on the pitch has shown little to suggest he could become the midfield general United have yearned for.

That said, his passing numbers are surprisingly positive compared to his time at Everton - 88 per cent pass success rate compared to 79.3% at Goodison Park in 2012-13 - but that doesn’t paint the whole picture.

Fellaini's deeper starting position has meant he has more room to spread play and recycle possession (therefore padding out his numbers) but he has been totally ineffective in the final third... he just isn’t an expansive ball player.

So far in the Premier League, Fellaini has failed to register an assist, averages 11.9 passes per game in the final third (compared to 22.3 at Everton last season) and has created just three chances in his 15 games (three in three this season for Everton, 40 in 31 last season).

On top of that, he has also shown that he can be rushed out of possession. At six foot four he lacks a burst of pace but it’s also becoming increasingly clear that he struggles to play fast one touch football. The combative Fellaini just doesn’t stack up well compared to his midfield counterparts across the league hwen it comes to ground duels.

There are 46 midfielders who are statistically more effective at winning 50-50 ground contests than the Belgian. Fellaini’s percentage success rate of 50.46% is below the average of 51.5% of players to have played in 10 games or more this campaign.

That he falls behind Michael Carrick (62.8%) and Tom Cleverley (51.8%) is surprising in itself. That he trails the likes of Juan Mata (52.5%), Eden Hazard (53.6%) and Philippe Coutinho (52.3%) suggests there is something wrong.

Pushing it further, you can argue that he isn’t even a danger in the air anymore - so often his forte at Everton. He has won 48 of 90 aerial duels (53.3%) at United which is above the average (47.2%) for players with 10 or more appearances under their belt but way short of the 90.5% he achieved last season.

A bruiser of a midfielder, Fellaini often treads a fine line. He was shown a red card in the club’s 0-0 draw at Real Sociedad and could have picked up one or two more - the elbow on Pablo Zabaleta a clear example in the Manchester derby - in a number of clumsy fouls.

There is a theory that he has been overawed by the size of Manchester United and the pressure that comes with playing for the Red Devils. In his defence, he has walked into a squad suddenly unsure of itself and playing well below the standards set in the Ferguson years, but something is clearly not right. His confidence looks shattered.

At Carrington, Fellaini trains well and is working hard on the technical side of his game. Big things are still expected of the Belgian and it is almost certain that he will still be at Old Trafford next season, when many around him will hope he finally adjusts to life as a small fish in a big pond.

Yet much like his manager, Fellaini is already swimming against the tide. If he is to survive and flourish at United he will know that big performances are required in the club’s remaining games this season.

He will also know that a club as big as United would never allow players to go through the motions - exactly what the Belgian must avoid if he is to turn opinions of the fans at Old Trafford.

Inflicting damage at his old stomping ground would be the perfect place to start a renaissance.